In recent years, developments for renewable energy have been in progress as a global warming countermeasure. For example, practical use of floating type off-shore wind power generators that transmit electricity from wind power generators, which are ocean floating installations, has been in progress.
To transmit electricity from ocean floating installations, submarine cables are used. A submarine cable includes three power cables that are assembled and twisted together for three-phase alternating current power transmission and armoring wires provided on the periphery of the core to support the cable load, of which the exterior is further extrusion coated with a plastic layer for protection from external damages.
Known submarine cables include a torque-balanced submarine cable including a linear assembly body, which is a plurality of a cable wire and a torsion reinforcing wire twisted together in one direction, and an armoring body provided on the periphery of the linear assembly body, in which armoring wires are twisted in the direction opposite to the direction in which the cable wires and the torsion reinforcing wires are twisted so that the torsional torque applied to the linear assembly body and the armoring body is cancelled.